linux/tools
Taeung Song 2e933b1274 perf annotate: Fix a bug of division by zero when calculating percent
Currently perf-annotate with --print-line can print
-nan(0x8000000000000) because of division by zero when calculating
percent. The division by zero happens when a sum of samples is zero in
symbol__get_source_line(), so fix it.

For example:

After running 'perf record' like below,

    $ perf record -e "{cycles,page-faults,branch-misses}" ./a.out

Before:

    $ perf annotate --stdio -l

  Sorted summary for file /home/taeung/workspace/a.out
  ----------------------------------------------

   32.89    -nan    7.04 a.c:38
   25.14    -nan    0.00 a.c:34
   16.26    -nan   56.34 a.c:31
   15.88    -nan    1.41 a.c:37
    5.67    -nan    0.00 a.c:39
    1.13    -nan   35.21 a.c:26
    0.95    -nan    0.00 a.c:44
    0.57    -nan    0.00 a.c:32
   Percent                 |      Source code & Disassembly of a.out for cycles (529 samples)
  -----------------------------------------------------------------------------------------
                         :
  ...

   a.c:26    0.57    -nan    4.23 :         40081a:       mov    %edi,-0x24(%rbp)
   a.c:26    0.00    -nan    9.86 :         40081d:       mov    %rsi,-0x30(%rbp)

  ...

However, if a sum of samples is zero (e.g. 'page-faults'),
skip calculating percent.

After:

    $ perf annotate --stdio -l

  Sorted summary for file /home/taeung/workspace/a.out
  ----------------------------------------------

   32.89    0.00    7.04 a.c:38
   25.14    0.00    0.00 a.c:34
   16.26    0.00   56.34 a.c:31
   15.88    0.00    1.41 a.c:37
    5.67    0.00    0.00 a.c:39
    1.13    0.00   35.21 a.c:26
    0.95    0.00    0.00 a.c:44
    0.57    0.00    0.00 a.c:32
   Percent                 |      Source code & Disassembly of old for cycles (529 samples)
  -----------------------------------------------------------------------------------------
                         :
  ...

  a.c:26    0.57    0.00    4.23 :         40081a:       mov    %edi,-0x24(%rbp)
  a.c:26    0.00    0.00    9.86 :         40081d:       mov    %rsi,-0x30(%rbp)

  ...

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1490598638-13947-3-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-03-27 15:04:56 -03:00
..
accounting tools: move accounting tool from Documentation 2016-09-23 13:07:15 -06:00
arch tools headers: Sync {tools/,}arch/powerpc/include/uapi/asm/kvm.h 2017-03-20 15:02:29 -03:00
build tools build: Use the same CC for feature detection and actual build 2017-03-03 19:07:19 -03:00
cgroup
firewire
gpio gpio-hammer: fix make consumer_label suitable to work on gpio-nails 2017-01-26 16:29:09 +01:00
hv Char/Misc driver patches for 4.10-rc1 2016-12-13 12:11:01 -08:00
iio iio: Add channel for Gravity 2017-01-05 13:02:25 +00:00
include tools include: Sync {,tools/}include/uapi/linux/perf_event.h 2017-03-17 11:49:09 -03:00
kvm/kvm_stat
laptop tools: move laptops dslm tool from Documentation 2016-09-23 13:07:21 -06:00
leds tools/leds: Add led_hw_brightness_mon program 2017-02-14 22:20:23 +01:00
lguest scripts/spelling.txt: add "overide" pattern and fix typo instances 2017-03-09 17:01:09 -08:00
lib tools lib api fs: Introduce sysfs__read_bool 2017-03-17 11:49:09 -03:00
net
nfsd
objtool objtool: Fix another GCC jump table detection issue 2017-03-07 08:42:55 +01:00
pcmcia tools: move pcmcia crc32hash tool from Documentation 2016-09-23 13:07:27 -06:00
perf perf annotate: Fix a bug of division by zero when calculating percent 2017-03-27 15:04:56 -03:00
power Power management turbostat utility updates for v4.11-rc1 2017-03-02 17:41:27 -08:00
scripts tools arch x86: Include asm/cmpxchg.h 2017-03-03 19:07:13 -03:00
spi spi: spidev_test: Fix input file check when transferring file 2016-11-04 09:56:09 -06:00
testing Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-03-14 21:31:23 -07:00
thermal/tmon
time
usb USB: changes for v4.11 2017-01-26 15:36:28 +01:00
virtio tools/virtio/ringtest: tweaks for s390 2017-01-19 23:46:32 +02:00
vm tools/vm: add missing Makefile rules 2017-02-22 16:41:26 -08:00
Makefile tools/leds: Add uledmon program for monitoring userspace LEDs 2016-11-22 12:07:02 +01:00